1. Field of the Invention
The present invention relates to a means for measuring the load current in a static convertor.
2. The Prior Art
Measuring of the load current in a static converter, for example for a high-voltage DC transmission, is usually carried out by measuring the direct current with the help of a transductor or possibly a Hall generator. Both these components are in themselves rather stable and reliable, but require feeding by auxiliary power to operate them. This involves a risk of a fault because the auxiliary power can drop out and it has proved difficult to secure a reliable reserve for this power. Disappearance of the auxiliary power causes a drop-out of the current signal to the control equipment of the convertor, which in turn usually leads to a surge in the static convertor.